Field of the Invention
The present invention relates to a scanning jig which is a member used in the field of dentistry for specifying a position of an embedded artificial tooth root (may be generally called an implant fixture or an implant body) to obtain a three-dimensional data.
Description of the Related Art
In the field of dentistry, a so-called dental implant technique has been largely applied as a prosthesis method for a defective tooth. The application of implant with the dental implant technique has more advantages compared with a conventional dental prosthesis, since it can make a state closer to that of a natural tooth.
A treatment with the implant is generally carried out by the following processes. That is: a hole is created to the jawbone at the defective site where the implant is to be applied; an artificial tooth root is embedded thereto; after the embedded artificial tooth root is sufficiently joined to the jawbone, an abutment which is a member for fixating a dental prosthesis is attached to the embedded artificial tooth root; then the dental prosthesis is arranged to the abutment.
The abutment is designed and produced individually for each patient in conformity with the depth and direction of the embedded artificial tooth root, and a state of the patient's oral cavity. In this regard, since the abutment has to be produced in conformity with a state of the artificial tooth root actually embedded, it is needed to know how the artificial tooth root is embedded before the abutment is produced. To this end, with an impression coping, information of the posture (depth and direction) of the artificial tooth root being embedded is transferred to an analog model which is a plaster model including an analog (a replica of the artificial tooth root). From the analogue model, the information of the artificial tooth root is obtained, whereby the abutment is produced.
Recently, the abutment is produced by means of an automatic cutting processing with three-dimensional shape data, and even an abutment having a complicated shape can be produced with a good accuracy. Therefore, in order to obtain the three-dimensional shape data for processing, it is needed to obtain a three-dimensional shape data including shapes of required parts in a person's oral cavity, an outer shape of the analog model, and postural information such as the depth and direction of the artificial tooth root.
However, among them, since the postural information (depth and direction) of the artificial tooth root is transferred to the analog and the analog is embedded inside the analog model, it is not possible to obtain the postural information of the artificial tooth root as a three-dimensional shape data as it is. On this issue, a scanning jig attached to the embedded analog in a manner to extend the analog, thereby being arranged such that one end side thereof projects from the analog model is used. That is, the scanning jig is attached coaxially to the analog, and an end portion of the scanning jig where the analog is not connected is exposed in a manner to project from the analog model. Therefore, it is possible to obtain the direction and positional information of the analog. By measuring three dimensionally the analog model with the scanning jig attached thereto to obtain a three-dimensional shape data, it is possible to obtain the orientation in a longitudinal direction of the analog embedded on an extension line of the scanning jig, and the positional information of the analog from a position of the end portion of the scanning jig (see Patent Document 1 for example).
In this regard, in order to obtain the three-dimensional shape data with an improved accuracy, in the obtained three-dimensional shape data of the analog model including the scanning jig, the three-dimensional shape data of the scanning jig is replaced with a three-dimensional shape data of the scanning jig which is prepared in advance.
Here, the term “scanning jig” is not necessarily widely used in the technical field of the present invention. However, since there is no unified name in the technical field, for a member which corresponds to the scanning jig having functions described above, the member is herein described as the “scanning jig”.